This invention relates to a device, and a method of using such a device, to provide support to the metatarsal arch of a human foot.
For the purposes of stabilizing the foot, the metatarsal heads constitute an arceate form referred to as the metatarsal arch. The metatarsal arch is present whenever the foot is supporting body weight, such as during standing, walking or running, because it allows the foot to function maximally as a supporting, stabilizing and balancing appendage. The toes flex as a result of the formation of the metatarsal arch, so that the distal phalanges contact squarely the underlying surface to permit balancing. In addition, the formation of the metatarsal arch permits the lateral edge of the foot""s sole to squarely contact the underlying surface, for the purpose of supporting body weight. Finally, various muscles and tendons characteristically interact to stabilize the foot, support body weight and permit balancing against underlying surfaces.
The term xe2x80x9ctoe-offxe2x80x9d or xe2x80x9cpush-offxe2x80x9d is used to denote the sequence of progressive movements normally experienced in a walking or running gait in preparation for movement from the neutral position, with a neutral position being defined as the subtalar joint being neither pronated nor supinated, to a propulsive phase of the gait cycle. Shoes may apply pressure to the dorsal (upper) surface of the foot because they are not correctly shaped to match the natural contours of the foot, and so prevent entirely the formation of the metatarsal arch. It is sometimes possible to shape a shoe to match the natural contours of the foot so as to not apply pressure to the foot when standing. However, if the shoe is not loose enough or soft enough to apply no pressure to the foot regardless of what position the foot is in, walking or running results in creasing across the top of the shoe when the foot pushes off, applying pressure to the foot and causing the metatarsal arch to flatten.
Metatarsal arch supports are intended to counter these interactions by providing a force opposed to flattening of the arch. However, although the idea of a metatarsal arch support is not new, existing designs are problematic because they provide support under areas of the foot designed to flatten out during normal foot movement and/or under areas of the foot not designed for direct weight bearing, or are incorrectly shaped to match the natural contours of the foot. As a result such designs create additional problems while attempting to solve the original one. Thus there continues to be a need for methods and devices to support the metatarsal arch without adventitiously creating other problems.
In one aspect, the invention is a metatarsal arch support for a foot in a shoe, the shoe comprising an insole, the foot comprising:
(a) a front part and a plurality of toes, the toes comprising first, second, third, fourth, and fifth proximal phalanges,
(b) first, second, third, fourth and fifth metatarsals joined to the first, second, third, fourth, and fifth proximal phalanges at first, second, third, fourth, and fifth metatarsal heads, respectively,
(c) a fleshy pad on a plantar surface of the foot comprising a front boundary underlying the first, second, third, fourth and fifth proximal phalanges and a back boundary underlying the first, second, third, fourth, and fifth metatarsals, comprising a recessed apex approximately between the first and second metatarsal heads,
(d) a first inflection boundary on the fleshy pad underlying the second, third, and fourth metatarsals,
(e) a second inflection boundary on the fleshy pad underlying the second, third and fourth proximal phalanges, approximately coinciding with the front boundary,
(f) a third inflection boundary on the fleshy pad between the first and second metatarsals, and
(g) a fourth inflection boundary on the fleshy pad between the fourth and fifth metatarsals,
the arch support comprising a base and an upper surface contoured to comfortably lie adjacent an area of the fleshy pad bounded by the first, second, third, and fourth inflection boundaries, the upper surface comprising a highest point, the base being at a shoe insole level, wherein the arch support rises from the base to the highest point, wherein the highest point underlies the recessed apex.
In another aspect, the invention is a method for supporting a foot in a shoe, the shoe comprising an insole, the foot comprising
(a) a front part and a plurality of toes, the toes comprising first, second, third, fourth, and fifth proximal phalanges,
(b) first, second, third, fourth and fifth metatarsals joined to the first, second, third, fourth, and fifth proximal phalanges at first, second, third, fourth, and fifth metatarsal heads, respectively,
(c) a fleshy pad on a plantar surface of the foot comprising a front boundary underlying the first, second, third, fourth and fifth proximal phalanges and a back boundary underlying the first, second, third, fourth, and fifth metatarsals, comprising a recessed apex approximately between the first and second metatarsal heads,
(d) a first inflection boundary on the fleshy pad underlying the second, third, and fourth metatarsals,
(e) a second inflection boundary on the fleshy pad underlying the second, third and fourth proximal phalanges, approximately coinciding with the front boundary,
(f) a third inflection boundary on the fleshy pad between the first and second metatarsals, and
(g) a fourth inflection boundary on the fleshy pad between the fourth and fifth metatarsals,
the method comprising providing in the shoe a metatarsal arch support for the foot, the arch support comprising a base and an upper surface contoured to comfortably lie adjacent an area of the fleshy pad bounded by the first, second, third, and fourth inflection boundaries, the upper surface comprising a highest point, the base being at a shoe insole level, wherein the arch support rises from the base to the highest point, wherein the highest point underlies the recessed apex.
In yet another aspect, the invention is a metatarsal arch supporting shoe insole for supporting a foot in a shoe, the foot comprising:
(a) a front part and a plurality of toes, the toes comprising first, second, third, fourth, and fifth proximal phalanges,
(b) first, second, third, fourth and fifth metatarsals joined to the first, second, third, fourth, and fifth proximal phalanges at first, second, third, fourth, and fifth metatarsal heads, respectively,
(c) a fleshy pad on a plantar surface of the foot comprising a front boundary underlying the first, second, third, fourth and fifth proximal phalanges and a back boundary underlying the first, second, third, fourth, and fifth metatarsals, comprising a recessed apex approximately between the first and second metatarsal heads,
(d) a first inflection boundary on the fleshy pad underlying the second, third, and fourth metatarsals,
(e) a second inflection boundary on the fleshy pad underlying the second, third and fourth proximal phalanges, approximately coinciding with the front boundary,
(f) a third inflection boundary on the fleshy pad between the first and second metatarsals, and
(g) a fourth inflection boundary on the fleshy pad between the fourth and fifth metatarsals,
the insole comprising a substantially flat section and a raised section, the raised section comprising a base and an upper surface contoured to comfortably lie adjacent an area of the fleshy pad bounded by the first, second, third, and fourth inflection boundaries, the upper surface comprising a highest point, the base being at a level contiguous with the flat section, wherein the arch support rises from the base to the highest point, wherein the highest point underlies the recessed apex.
In a further aspect, the invention is a shoe comprising an integral metatarsal arch supporting shoe insole for supporting a foot, the foot comprising:
(a) a front part and a plurality of toes, the toes comprising first, second, third, fourth, and fifth proximal phalanges,
(b) first, second, third, fourth and fifth metatarsals joined to the first, second, third, fourth, and fifth proximal phalanges at first, second, third, fourth, and fifth metatarsal heads, respectively,
(c) a fleshy pad on a plantar surface of the foot comprising a front boundary underlying the first, second, third, fourth and fifth proximal phalanges and a back boundary underlying the first, second, third, fourth, and fifth metatarsals, comprising a recessed apex approximately between the first and second metatarsal heads,
(d) a first inflection boundary on the fleshy pad underlying the second, third, and fourth metatarsals,
(e) a second inflection boundary on the fleshy pad underlying the second, third and fourth proximal phalanges, approximately coinciding with the front boundary,
(f) a third inflection boundary on the fleshy pad between the first and second metatarsals, and
(g) a fourth inflection boundary on the fleshy pad between the fourth and fifth metatarsals,
the insole comprising a substantially flat section and a raised section, the raised section comprising a base and an upper surface contoured to comfortably lie adjacent an area of the fleshy pad bounded by the first, second, third, and fourth inflection boundaries, the upper surface comprising a highest point, the base being at a level contiguous with the flat section, wherein the arch support rises from the base to the highest point, wherein the highest point underlies the recessed apex, wherein the insole is permanently affixed to the shoe.
It has been found that good metatarsal arch support can be provided by the methods and devices of this invention.